 
 (def v2 (conj v 1e6)) ; 'conj' a value to 'v'
 
-(fact "Clojures data structures are immuatable"
+(fact "Clojure's data structures are immutable"
   (count v)
   => 1000000
   (count v2)


A comparator is a two argument function that returns a positive
 integer if the first argument is > than the second, a negative
 if the second arguent is greater, zero if they are equal

All Clojure functions implement Comparator, so any two argument
 predicate will do

  (fact
    (get [:a :b :c] 2)
    => :c)
  (fact "Oops!"
    (nth  [:a :b :c] 3)
    => (throws IndexOutOfBoundsException))
  (fact "Better."
